This invention relates generally to electrical connectors for printed circuit board assemblies, and more specifically to a card edge connector including shorting contacts.
Typically, a mother board and one or more daughter boards are used to transfer signals between respective assemblies used in a computer or other electronic equipment. In some types of equipment, the mother and daughter boards may be arranged perpendicular to each other, sometimes referred to as a xe2x80x9ccard edgexe2x80x9d configuration, depending upon the design of the overall product. A card edge connector extends between and couples the mother and daughter boards with a number of opposed electrical contacts. One end of each of the contacts is secured to the mother board and the opposite end of each of the contacts is fitted within a slot in the connector such that a daughter board may be received in the slot between the ends of opposed contacts. When the daughter board is removed from the slot, the opposed contacts come together to form an electrical shorting circuit through the connector. The reliability of these shorting contacts is influential to the efficiency of the associated equipment.
Conventionally, the card edge contacts are bent or bowed members which engage one another across an entire width of the respective contacts when the daughter board is removed. A dimple has sometimes been used on a surface of the shorting contacts to obtain contact stress against an opposing contact. Dust and debris, however, may collect at the interface between the mother board and the daughter board, or an oxide film may form on the opposing contacts of the edge connector. Debris and films may compromise the electrical connection between the opposed shorting contacts and may result in malfunction of the electronic equipment.
Shorting contacts have been developed which include radiused protrusions such that when the protrusions are located opposite one another in a housing, wiping movement between the protrusions creates a moving point of connection which overcomes film or debris on the contacts to improve the reliability of the shorting connection between the contacts. See, for example, U.S. Pat. Nos. 5,277,607 and 5,366,382. The protrusions, however, may become misaligned with one another and compromise the shorting connection. Additionally, the protrusions are designed to separate when a daughter board is inserted into the connector in order to break the shorting connection. However, if the daughter board is incompletely or incorrectly inserted into the connector, the connection between shorting contacts will be broken and electrical malfunction and component damage may result.
In accordance with an exemplary embodiment of the invention, a contact system comprises at least one opposed pair of contacts. Each of the contacts of the pair comprise a resilient rear leg, a guide section extending from the rear leg, and a contact interface extending from the guide section. The contact interface comprises a furcated surface adapted to establish multiple points of contact with a mating contact interface.
Optionally, the furcated surface comprises a first contact beam and a second contact beam separated by a slot. At least one contoured footing extends from one of the first and second contact beams to establish multiple contact points with a mating interface. In one embodiment three separate points of contact are established with a mating contact interface.
According to another exemplary embodiment of the invention, an electrical connector comprises a pair of contacts arranged opposed to one another. Each of the contacts comprise a furcated contact interface, and the furcated contact interfaces of the pair of contacts engage one another until a printed circuit board is fully inserted between the contact interfaces.
According to another exemplary embodiment, an electrical connector comprises a housing configured to receive a circuit board and comprising at least one tapered interior wall. A pair of contacts are provided in the housing and are arranged opposed to one another. At least one of the pair of contacts comprises a resilient rear leg situated adjacent the tapered interior wall and a resilient contact section extending from the rear leg. The contact section includes a contact interface comprising at least one contact beam adapted to create separate first and second points of contact when the contact interface is engaged to a mating contact interface.
According to another exemplary embodiment of the invention, an electrical card edge connector is provided. The connector comprises a housing configured to receive an edge of a circuit board, and first and second contacts situated in the housing and arranged in a mating opposite pair. At least one of the first and second contacts comprises a resilient rear leg situated adjacent a tapered interior wall of the housing, and a guide section extending from the rear leg. The guide section engages the circuit board as the circuit board is received in the housing and a resilient contact interface extends from the guide section. The contact interface comprises a furcated contact interface engaging a mating contact interface until the circuit board is fully inserted between the first and second contacts. The resilient leg flexes when the circuit board engages the guide section to receive the printed circuit board without separating the contact interfaces from one another until the circuit board is inserted a predetermined distance into the slot.